ReaderPen and LingoPen allows local storage of text files and voice memos.
Each text file must not exceed 64kB, which equals appr. 7,5 A4 pages of tightly written text in font size 12.
1GB of free space (both ReaderPen and LingoPen offer >2GB user space) can host 130,000 A4 pages OR 24 hours worth of voice memos in MP3 format / middle quality.